1. Field of the Invention
The present invention relates to a wireless communication apparatus, a cordless telephone, a display operation control method, a program, and a storage medium. In particular, the present invention relates to a wireless communication apparatus and a cordless telephone, which are comprised of a slave unit and a master unit, with which the slave unit located remotely from the master unit performs conversation with an opposite party by using a wireless radio wave through the master unit connected to a telephone line, a display operation control method, a program for implementing the method, and a storage medium storing the program.
2. Description of the Related Art
A conventional wireless communication apparatus such as a cordless telephone has a function called “carrier sense” of detecting in advance whether the frequency of each conversation channel is being used, when starting communication using the communication apparatus, and selecting a vacant channel that is not currently used while avoiding other channels that are currently used by other cordless telephones, to thereby guarantee a normal communication operation.
Even if conversation is started using the channel selected by the above carrier sense function or carrier sense, if a noise that has such a low level as is not detected by the carrier sense function occurs and in particular the noise has burst-like regularity, the noise acts as an annoyance for the conversation, resulting in degraded conversation quality. Such a noise does not raise a serious problem with monochrome displaying using a small-sized display, because the amount of data transferred to the display is small. Therefore, the occurrence of noise during conversion using a wireless communication apparatus has conventionally been suppressed by the following prior art methods.
Japanese Laid-Open Patent Publication (Kokai) No. 2001-332994 discloses a small-sized wireless apparatus as represented by a cellular phone, in which to suppress a noise generated from a logic circuit in a receiving section of the wireless apparatus, the power supply is stopped to a data conversion section, an LCD driver input/output control section, and the like that are not directly related to a receiving operation.
Japanese Laid-Open Patent Publication (Kokai) No. 07-336520 discloses a facsimile machine having a cordless telephone, in which to prevent occurrence of a noise from a facsimile section whose operation clock has a high frequency, control is provided such that a CPU of the facsimile section is set in a non-operating mode when no facsimile operation is carried out.
Japanese Laid-Open Patent Publication (Kokai) No. 08-293839 discloses a cordless telephone equipped with a facsimile, in which to prevent the intrusion of a noise from the facsimile system into the cordless telephone system, a CPU that controls the facsimile reception is put into a halt state when facsimile transmission/reception is not carried out.
Further, Japanese Laid-Open Patent Publication (Kokai) No. 11-127300 discloses a facsimile machine having a cordless telephone, in which oscillation of an IC that is a source of a radiant noise is stopped in advance in order to prevent the noise from interfering with the operation of a control channel of the cordless telephone. To this end, the supply of a clock to a logic IC of an image processor is stopped when the facsimile machine is on standby, and further, the cordless telephone is inhibited from being used during a copy operation and copying is inhibited from being carried out when the control channel of the cordless telephone is used for phone conversion.
In recent years, however, with advancement of information and communication technology in the field of wireless communication apparatuses (cordless telephones, for example), communication carriers and the like have launched new services for browsing information using fixed-line phones. With such surfaces, phone displays have developed from monochrome display to color display, which has led to an increased amount of data transferred to the displays, and as a result, the above noise problem has become more serious. That is, the performance of wireless communication apparatuses (cordless telephones, for example) has been enhanced so that the amount of data required for displays has increased to several tens as large as the previously required amount. In addition, the data transfer speed has further increased and hence the data amount has increased, which results in burst-like noise occurring during wireless communication.
Also, the displays have become capable of carrying out color displaying to cope with wait screens and moving screens such as a screen saver, so that burst-like data is periodically transferred via system buses.